Origin not entirely certain. However, most historians believe that it is onomatopoeia for the sound a blimp makes when thumped. Although there is some disagreement among historians, credit for coining the term is usually given to Lt. A.D. Conningham of the British Royal Navy in 1915.

There is an often repeated, but false, alternative explanation for the term. The erroneous story is that at some time in the early 20th century, the United Statesmilitary had two classes for airships: Type A-rigid and Type B-limp, hence “blimp”. In fact,

“there was no American ‘A-class’ of airships as such—all military aircraft, heavier or lighter-than-air were designated with ‘A’ until the appearance of B-class airships in May 1917. There was an American B airship—but there seems to be no record of any official designation of non-rigids as ‘limp’. Further, according to the Oxford Dictionary, the first appearance of the word in print was in 1916, in England, a year before the first B-class airship.” (“Etymology of ‘Blimp’” by Dr. A. D. Topping, AAHS Journal, Winter 1963.)